(343b) Design and Economic Analysis of IGCC Power Plants with CO2 Capture

Power producing industry has largely relied on coal as a fuel source and will continue to depend on it for coming decades under the current situation. However, in order to curtail CO₂ emissions while keeping high efficiency and economic feasibility of the processes is a key challenge. Post combustion coal-fired power plants usually have lower capital costs and cost of electricity without CO₂ capture. On the other hand, pre-combustion plants tend to be less expensive if the current CO₂capture systems are to be added. This analysis suggests that pre-combustion technology for the power generation can be an attractive option if carbon capture and storage (CCS) technology is implemented on a large scale. In this study IGCC process has been simulated in order to analyze the overall plant output with CO₂ capture using a physical solvent. Three design schemes have been developed to analyze the overall plant performance and economics. In order to ensure a fair evaluation of analysis, a consistent and transparent methodology has been followed for all the cases. First two cases use the water gas shift reactions scheme with sour shift catalysis process. The resulted syngas free of CO₂ can either be combusted by using air or O₂. The first case uses air as an oxidant for burning H₂ and the combustor temperature is controlled by air as well. In the second case, O₂ is used as an oxidizing agent in the H₂ combustion. However, combustion temperature control is achieved by recycling the captured CO₂. In the third model, WGS reactor has been removed. The syngas composed of CO and H₂ is sent directly for combustion which makes it similar to the oxy-fuel combustion process. In this way, captured CO₂ can be recycled back to control the combustor temperature in 2^nd and 3^rdcase. The results showed that the net power generation capacity and efficiencies calculated for case 1, case 2 and case 3 are 375 MWe, 354 MWe, 388 MWe and 35.87%, 33.89%, 37.15% respectively. Finally, an economic analysis has been performed which shows that the total investment cost (TIC) and operation and maintenance (O&M) required per unit (MW) of electricity generated for case 1, case 2 and case 3 is (2.97, 3.40, 2.64) and (0.2486, 0.2706, 0.2242) Mâ?¬â??s respectively. With the highest net power generation capacity and least TIC and O&M cost requirements, case 3 has been evaluated as the most feasible design. If the sole purpose of IGCC power plant is power generation with CO₂ capture, case 3 design offers a cost reduction of 8.17% and 6.59% in the total investment and O&M cost requirements respectively as compared to the base case design.